But that money you’re putting towards the mortgage belongs to future-you (minus interest, and assuming property prices at least stay the same). It’s a savings account.
To get the money back you have to sell your property, and then where are you going to live? Sure it's great if you want to then move to a cheap area, but what if you want to stay near your friends & family?
(Yes, there are some alternatives like HELOC or reverse mortgage, but I don't think they are generally that great except for very specific situations)
Sounds easy, in practice it’s much harder. Spend years building a life making money, have your entire social circle and your kids’ lives somewhere. You don’t just leave. Why do most of our parents still live in the same place or move to near where their kids live (also other HCOL areas)?
Because most parents didn't have the foresight to only invest a few years to kickstart their career and bank accounts to greater heights and leave after.
Times have changed and the writing is on the wall for individuals to GTFO after a few years now. Gentrification is far more rampant and obvious, and anyone moving to a big city has a wealth of information to draw from.